Abstract: FR-PO573
Abiraterone Induced Hypokalemia in Treatment of Castration Resistant Prostate Cancer
Session Information
- Trainee Case Reports - III
October 26, 2018 | Location: Exhibit Hall, San Diego Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Trainee Case Reports
- 901 Fluid and Electrolytes: Basic
Authors
- Asfar, Waleed, Medical University of South Carolina, Charleston, South Carolina, United States
- Budisavljevic, Milos N., Medical University of South Carolina, Charleston, South Carolina, United States
- Elliott, Andrew B., Medical University of South Carolina, Charleston, South Carolina, United States
Introduction
Abiraterone was approved in combination with prednisone for the treatment of metastatic Castration Resistant Prostate Cancer ( CRPC) who recieved chemotherapy. In 2018 FDA expanded the indication to include chemotherapy naive patients. Most common side effects associated with abiraterone include fatigue, diarrhea, hypertension, elevated liver enzymes, and hypokalemia. Abiraterone inhibits CYP17A1, the rate limiting hydroxylase in androgen and steroids synthetic pathway. This causes ACTH level to increase, leading to secondary excess in
mineralocorticoids. This secondary excess manifests as hypertension,hypokalemia, and fluid overload. Prednisone is co-administered to suppress the hypothalamic-pituitary-adrenal axis and diminish the symptoms of mineralocorticoid excess.
Case Description
We Describe a case of a 65 year old male with history of hypertension, dyslipidemia, hypothyroidism and prostate cancer. He was diagnosed with Prostate cancer in 2005 and recieved total prostatectomy. In 2012 he developed biochemical relapse and recieved radiation and androgen depreviation therapy. In 2015 he was found to have bone metastasis and recieved radiation therapy to the cervical spine and started on abiraterone and prednisone therapy early 2016. He was later found to have avascular necrosis of the left femoral head and decided to stop prednisone as he was worried about his bone health. He was found to have Hypokalemia and worsening control of blood pressure on follow up with primary care, his serum potassium was 2.5 with a serum bicarb of 25. He was started on oral potassium supplementation but his Hypokalemia persisted. He was seen by nephrology as an outpatient, his exam was significant for elevated BP and trace lower extremity edema. serum aldosterone to renin was low at 2.9. He was started on aldactone with improvement in his serum potassium on follow up.
Discussion
With the recent expansion of the FDA approval more prostate cancer patients will be treated with abiraterone, understanding the mechanism of action of abiraterone and resulting side effects is crucial as it can prevent dangerous arrhythmias and outcomes.
Nephrology input is needed in manging these patient along with primary care.
Patient with contraindications to steroids should be started on eplerenone or aldactone therapy.